The present invention relates to a device for automatically removing an inserted-and-beat-up weft on weaving machines.
A general aim common to all producers of weaving appliances is to increase their useful performance. This aim can be realized in several ways, among them by minimizing the time required to repair weft defects; i.e., incorrectly-inserted wefts. For this purpose, automatic devices for weft-defect removal can be used.
For removing an incorrectly-inserted weft, many solutions are known The most widely used solution utilizes the fact that incorrectly-inserted wefts remain connected with the supply on a metering member after pick and beat-up procedures have been carried out. In the next step, after a short reverse motion of the weaving machine and loosening of the incorrectly-inserted weft from the interlacing by the warp threads, another weft, still connected with the incorrectly-inserted weft, is picked to the shed end side. By pulling this weft, the incorrectly-inserted weft is removed.
Several drawbacks are inherent to this solution. The need to keep the incorrectly-inserted weft in connection with the supply on the metering member imposes heavy demands on the reaction speed of the locking device, which prevents the inserted weft from being separated. Another major drawback consists in the described device failing to remove wefts that have suffered rupture during the pick so that one weft part is woven-in on the entering side of the weaving machine, and the other part is woven-in on the shed end side.
Eliminating the drawbacks of the known solutions is an object of the present device. The object of the present invention is realized in a device for automatically removing inserted-and-beat-up wefts. The device comprises a rotary stripping brush including on an exterior periphery agitation hairs for urging an inserted-and-beat-up weft away from a grip of a shed. The rotary stripping brush further includes gaseous feed jets on an exterior periphery of the brush for urging, in cooperation with the agitation hairs, the inserted-and-beat-up weft away from the grip of the shed.
Amongst the advantages of the present device, it becomes unnecessary to ensure that the weft to be unravelled is unseparated from the supply on the metering member; further, the possibility exists to remove several (more than one) preceding wefts; and, finally, it permits removal even of wefts that have suffered rupture during machine operation. Owing to these advantages, the present device is superior to the known devices.